What is an Immunoassay or ELISA?
Immunoassays are quick and accurate tests that can be used on-site and in the laboratory to detect specific molecules (How do I run an ELISA?). Immunoassays rely on the inherent ability of an antibody to bind to the specific structure of a molecule. Antibodies are proteins generated by animals in response to the invasion of a foreign molecule (antigen) into the body. Antibodies are found in blood and tissue fluids and will bind to the antigen whenever it is encountered. Because antibodies are developed based on the specific three-dimensional structure of an antigen, or analyte, they are highly specific and will bind only to that structure. Once purified from the blood, monoclonal and polyclonal antibodies are ideal assay reagents to detect and monitor specific target molecules with limited interferences from other substances. 4 typical formats are: monoclonal-polyclonal sandwich assays, competitive inhibition assays, antigen-down immunoassays, and rapid assays. History of Immunoassays